diff --git a/frontends/ast/genrtlil.cc b/frontends/ast/genrtlil.cc
index d81c53dfb..9327b34ee 100644
--- a/frontends/ast/genrtlil.cc
+++ b/frontends/ast/genrtlil.cc
@@ -45,7 +45,7 @@ using namespace AST_INTERNAL;
 // helper function for creating RTLIL code for unary operations
 static RTLIL::SigSpec uniop2rtlil(AstNode *that, IdString type, int result_width, const RTLIL::SigSpec &arg, bool gen_attributes = true)
 {
-	IdString name = stringf("%s$%s:%d$%d", type.c_str(), that->filename.c_str(), that->location.first_line, autoidx++);
+	IdString name = stringf("%s$%s:%d$%d", type.c_str(), RTLIL::encode_filename(that->filename).c_str(), that->location.first_line, autoidx++);
 	RTLIL::Cell *cell = current_module->addCell(name, type);
 	set_src_attr(cell, that);
 
@@ -77,7 +77,7 @@ static void widthExtend(AstNode *that, RTLIL::SigSpec &sig, int width, bool is_s
 		return;
 	}
 
-	IdString name = stringf("$extend$%s:%d$%d", that->filename.c_str(), that->location.first_line, autoidx++);
+	IdString name = stringf("$extend$%s:%d$%d", RTLIL::encode_filename(that->filename).c_str(), that->location.first_line, autoidx++);
 	RTLIL::Cell *cell = current_module->addCell(name, ID($pos));
 	set_src_attr(cell, that);
 
@@ -104,7 +104,7 @@ static void widthExtend(AstNode *that, RTLIL::SigSpec &sig, int width, bool is_s
 // helper function for creating RTLIL code for binary operations
 static RTLIL::SigSpec binop2rtlil(AstNode *that, IdString type, int result_width, const RTLIL::SigSpec &left, const RTLIL::SigSpec &right)
 {
-	IdString name = stringf("%s$%s:%d$%d", type.c_str(), that->filename.c_str(), that->location.first_line, autoidx++);
+	IdString name = stringf("%s$%s:%d$%d", type.c_str(), RTLIL::encode_filename(that->filename).c_str(), that->location.first_line, autoidx++);
 	RTLIL::Cell *cell = current_module->addCell(name, type);
 	set_src_attr(cell, that);
 
@@ -138,7 +138,7 @@ static RTLIL::SigSpec mux2rtlil(AstNode *that, const RTLIL::SigSpec &cond, const
 	log_assert(cond.size() == 1);
 
 	std::stringstream sstr;
-	sstr << "$ternary$" << that->filename << ":" << that->location.first_line << "$" << (autoidx++);
+	sstr << "$ternary$" << RTLIL::encode_filename(that->filename) << ":" << that->location.first_line << "$" << (autoidx++);
 
 	RTLIL::Cell *cell = current_module->addCell(sstr.str(), ID($mux));
 	set_src_attr(cell, that);
@@ -321,7 +321,7 @@ struct AST_INTERNAL::ProcessGenerator
 		LookaheadRewriter la_rewriter(always);
 
 		// generate process and simple root case
-		proc = current_module->addProcess(stringf("$proc$%s:%d$%d", always->filename.c_str(), always->location.first_line, autoidx++));
+		proc = current_module->addProcess(stringf("$proc$%s:%d$%d", RTLIL::encode_filename(always->filename).c_str(), always->location.first_line, autoidx++));
 		set_src_attr(proc, always);
 		for (auto &attr : always->attributes) {
 			if (attr.second->type != AST_CONSTANT)
@@ -1776,7 +1776,7 @@ RTLIL::SigSpec AstNode::genRTLIL(int width_hint, bool sign_hint)
 	case AST_MEMRD:
 		{
 			std::stringstream sstr;
-			sstr << "$memrd$" << str << "$" << filename << ":" << location.first_line << "$" << (autoidx++);
+			sstr << "$memrd$" << str << "$" << RTLIL::encode_filename(filename) << ":" << location.first_line << "$" << (autoidx++);
 
 			RTLIL::Cell *cell = current_module->addCell(sstr.str(), ID($memrd));
 			set_src_attr(cell, this);
@@ -1814,7 +1814,7 @@ RTLIL::SigSpec AstNode::genRTLIL(int width_hint, bool sign_hint)
 	case AST_MEMINIT:
 		{
 			std::stringstream sstr;
-			sstr << "$meminit$" << str << "$" << filename << ":" << location.first_line << "$" << (autoidx++);
+			sstr << "$meminit$" << str << "$" << RTLIL::encode_filename(filename) << ":" << location.first_line << "$" << (autoidx++);
 
 			SigSpec en_sig = children[2]->genRTLIL();
 
@@ -1869,7 +1869,7 @@ RTLIL::SigSpec AstNode::genRTLIL(int width_hint, bool sign_hint)
 
 			IdString cellname;
 			if (str.empty())
-				cellname = stringf("%s$%s:%d$%d", celltype.c_str(), filename.c_str(), location.first_line, autoidx++);
+				cellname = stringf("%s$%s:%d$%d", celltype.c_str(), RTLIL::encode_filename(filename).c_str(), location.first_line, autoidx++);
 			else
 				cellname = str;
 
diff --git a/frontends/ast/simplify.cc b/frontends/ast/simplify.cc
index 2d9d6dc79..49bf9af09 100644
--- a/frontends/ast/simplify.cc
+++ b/frontends/ast/simplify.cc
@@ -1240,7 +1240,7 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
 
 				// create the indirection wire
 				std::stringstream sstr;
-				sstr << "$indirect$" << ref->name.c_str() << "$" << filename << ":" << location.first_line << "$" << (autoidx++);
+				sstr << "$indirect$" << ref->name.c_str() << "$" << RTLIL::encode_filename(filename) << ":" << location.first_line << "$" << (autoidx++);
 				std::string tmp_str = sstr.str();
 				add_wire_for_ref(ref, tmp_str);
 
@@ -2127,7 +2127,7 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
 			std::swap(data_range_left, data_range_right);
 
 		std::stringstream sstr;
-		sstr << "$mem2bits$" << str << "$" << filename << ":" << location.first_line << "$" << (autoidx++);
+		sstr << "$mem2bits$" << str << "$" << RTLIL::encode_filename(filename) << ":" << location.first_line << "$" << (autoidx++);
 		std::string wire_id = sstr.str();
 
 		AstNode *wire = new AstNode(AST_WIRE, new AstNode(AST_RANGE, mkconst_int(data_range_left, true), mkconst_int(data_range_right, true)));
@@ -2714,14 +2714,14 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
 			// mask and shift operations, disabled for now
 
 			AstNode *wire_mask = new AstNode(AST_WIRE, new AstNode(AST_RANGE, mkconst_int(source_width-1, true), mkconst_int(0, true)));
-			wire_mask->str = stringf("$bitselwrite$mask$%s:%d$%d", filename.c_str(), location.first_line, autoidx++);
+			wire_mask->str = stringf("$bitselwrite$mask$%s:%d$%d", RTLIL::encode_filename(filename).c_str(), location.first_line, autoidx++);
 			wire_mask->attributes[ID::nosync] = AstNode::mkconst_int(1, false);
 			wire_mask->is_logic = true;
 			while (wire_mask->simplify(true, false, false, 1, -1, false, false)) { }
 			current_ast_mod->children.push_back(wire_mask);
 
 			AstNode *wire_data = new AstNode(AST_WIRE, new AstNode(AST_RANGE, mkconst_int(source_width-1, true), mkconst_int(0, true)));
-			wire_data->str = stringf("$bitselwrite$data$%s:%d$%d", filename.c_str(), location.first_line, autoidx++);
+			wire_data->str = stringf("$bitselwrite$data$%s:%d$%d", RTLIL::encode_filename(filename).c_str(), location.first_line, autoidx++);
 			wire_data->attributes[ID::nosync] = AstNode::mkconst_int(1, false);
 			wire_data->is_logic = true;
 			while (wire_data->simplify(true, false, false, 1, -1, false, false)) { }
@@ -2732,7 +2732,7 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
 			shift_expr->detectSignWidth(shamt_width_hint, shamt_sign_hint);
 
 			AstNode *wire_sel = new AstNode(AST_WIRE, new AstNode(AST_RANGE, mkconst_int(shamt_width_hint-1, true), mkconst_int(0, true)));
-			wire_sel->str = stringf("$bitselwrite$sel$%s:%d$%d", filename.c_str(), location.first_line, autoidx++);
+			wire_sel->str = stringf("$bitselwrite$sel$%s:%d$%d", RTLIL::encode_filename(filename).c_str(), location.first_line, autoidx++);
 			wire_sel->attributes[ID::nosync] = AstNode::mkconst_int(1, false);
 			wire_sel->is_logic = true;
 			wire_sel->is_signed = shamt_sign_hint;
@@ -2809,7 +2809,7 @@ skip_dynamic_range_lvalue_expansion:;
 	if (stage > 1 && (type == AST_ASSERT || type == AST_ASSUME || type == AST_LIVE || type == AST_FAIR || type == AST_COVER) && current_block != NULL)
 	{
 		std::stringstream sstr;
-		sstr << "$formal$" << filename << ":" << location.first_line << "$" << (autoidx++);
+		sstr << "$formal$" << RTLIL::encode_filename(filename) << ":" << location.first_line << "$" << (autoidx++);
 		std::string id_check = sstr.str() + "_CHECK", id_en = sstr.str() + "_EN";
 
 		AstNode *wire_check = new AstNode(AST_WIRE);
@@ -2918,7 +2918,7 @@ skip_dynamic_range_lvalue_expansion:;
 			newNode = new AstNode(AST_BLOCK);
 
 			AstNode *wire_tmp = new AstNode(AST_WIRE, new AstNode(AST_RANGE, mkconst_int(width_hint-1, true), mkconst_int(0, true)));
-			wire_tmp->str = stringf("$splitcmplxassign$%s:%d$%d", filename.c_str(), location.first_line, autoidx++);
+			wire_tmp->str = stringf("$splitcmplxassign$%s:%d$%d", RTLIL::encode_filename(filename).c_str(), location.first_line, autoidx++);
 			current_ast_mod->children.push_back(wire_tmp);
 			current_scope[wire_tmp->str] = wire_tmp;
 			wire_tmp->attributes[ID::nosync] = AstNode::mkconst_int(1, false);
@@ -2956,7 +2956,7 @@ skip_dynamic_range_lvalue_expansion:;
 			(children[0]->children.size() == 1 || children[0]->children.size() == 2) && children[0]->children[0]->type == AST_RANGE)
 	{
 		std::stringstream sstr;
-		sstr << "$memwr$" << children[0]->str << "$" << filename << ":" << location.first_line << "$" << (autoidx++);
+		sstr << "$memwr$" << children[0]->str << "$" << RTLIL::encode_filename(filename) << ":" << location.first_line << "$" << (autoidx++);
 		std::string id_addr = sstr.str() + "_ADDR", id_data = sstr.str() + "_DATA", id_en = sstr.str() + "_EN";
 
 		int mem_width, mem_size, addr_bits;
@@ -3228,7 +3228,7 @@ skip_dynamic_range_lvalue_expansion:;
 					AstNode *reg = new AstNode(AST_WIRE, new AstNode(AST_RANGE,
 							mkconst_int(width_hint-1, true), mkconst_int(0, true)));
 
-					reg->str = stringf("$past$%s:%d$%d$%d", filename.c_str(), location.first_line, myidx, i);
+					reg->str = stringf("$past$%s:%d$%d$%d", RTLIL::encode_filename(filename).c_str(), location.first_line, myidx, i);
 					reg->is_reg = true;
 					reg->is_signed = sign_hint;
 
@@ -3733,7 +3733,7 @@ skip_dynamic_range_lvalue_expansion:;
 
 
 		std::stringstream sstr;
-		sstr << str << "$func$" << filename << ":" << location.first_line << "$" << (autoidx++) << '.';
+		sstr << str << "$func$" << RTLIL::encode_filename(filename) << ":" << location.first_line << "$" << (autoidx++) << '.';
 		std::string prefix = sstr.str();
 
 		AstNode *decl = current_scope[str];
@@ -4586,7 +4586,7 @@ static void mark_memories_assign_lhs_complex(dict<AstNode*, pool<std::string>> &
 	if (that->type == AST_IDENTIFIER && that->id2ast && that->id2ast->type == AST_MEMORY) {
 		AstNode *mem = that->id2ast;
 		if (!(mem2reg_candidates[mem] & AstNode::MEM2REG_FL_CMPLX_LHS))
-			mem2reg_places[mem].insert(stringf("%s:%d", that->filename.c_str(), that->location.first_line));
+			mem2reg_places[mem].insert(stringf("%s:%d", RTLIL::encode_filename(that->filename).c_str(), that->location.first_line));
 		mem2reg_candidates[mem] |= AstNode::MEM2REG_FL_CMPLX_LHS;
 	}
 }
@@ -4614,14 +4614,14 @@ void AstNode::mem2reg_as_needed_pass1(dict<AstNode*, pool<std::string>> &mem2reg
 			// activate mem2reg if this is assigned in an async proc
 			if (flags & AstNode::MEM2REG_FL_ASYNC) {
 				if (!(mem2reg_candidates[mem] & AstNode::MEM2REG_FL_SET_ASYNC))
-					mem2reg_places[mem].insert(stringf("%s:%d", filename.c_str(), location.first_line));
+					mem2reg_places[mem].insert(stringf("%s:%d", RTLIL::encode_filename(filename).c_str(), location.first_line));
 				mem2reg_candidates[mem] |= AstNode::MEM2REG_FL_SET_ASYNC;
 			}
 
 			// remember if this is assigned blocking (=)
 			if (type == AST_ASSIGN_EQ) {
 				if (!(proc_flags[mem] & AstNode::MEM2REG_FL_EQ1))
-					mem2reg_places[mem].insert(stringf("%s:%d", filename.c_str(), location.first_line));
+					mem2reg_places[mem].insert(stringf("%s:%d", RTLIL::encode_filename(filename).c_str(), location.first_line));
 				proc_flags[mem] |= AstNode::MEM2REG_FL_EQ1;
 			}
 
@@ -4638,11 +4638,11 @@ void AstNode::mem2reg_as_needed_pass1(dict<AstNode*, pool<std::string>> &mem2reg
 			// remember where this is
 			if (flags & MEM2REG_FL_INIT) {
 				if (!(mem2reg_candidates[mem] & AstNode::MEM2REG_FL_SET_INIT))
-					mem2reg_places[mem].insert(stringf("%s:%d", filename.c_str(), location.first_line));
+					mem2reg_places[mem].insert(stringf("%s:%d", RTLIL::encode_filename(filename).c_str(), location.first_line));
 				mem2reg_candidates[mem] |= AstNode::MEM2REG_FL_SET_INIT;
 			} else {
 				if (!(mem2reg_candidates[mem] & AstNode::MEM2REG_FL_SET_ELSE))
-					mem2reg_places[mem].insert(stringf("%s:%d", filename.c_str(), location.first_line));
+					mem2reg_places[mem].insert(stringf("%s:%d", RTLIL::encode_filename(filename).c_str(), location.first_line));
 				mem2reg_candidates[mem] |= AstNode::MEM2REG_FL_SET_ELSE;
 			}
 		}
@@ -4656,7 +4656,7 @@ void AstNode::mem2reg_as_needed_pass1(dict<AstNode*, pool<std::string>> &mem2reg
 
 		// flag if used after blocking assignment (in same proc)
 		if ((proc_flags[mem] & AstNode::MEM2REG_FL_EQ1) && !(mem2reg_candidates[mem] & AstNode::MEM2REG_FL_EQ2)) {
-			mem2reg_places[mem].insert(stringf("%s:%d", filename.c_str(), location.first_line));
+			mem2reg_places[mem].insert(stringf("%s:%d", RTLIL::encode_filename(filename).c_str(), location.first_line));
 			mem2reg_candidates[mem] |= AstNode::MEM2REG_FL_EQ2;
 		}
 	}
@@ -4846,7 +4846,7 @@ bool AstNode::mem2reg_as_needed_pass2(pool<AstNode*> &mem2reg_set, AstNode *mod,
 			children[0]->children[0]->children[0]->type != AST_CONSTANT)
 	{
 		std::stringstream sstr;
-		sstr << "$mem2reg_wr$" << children[0]->str << "$" << filename << ":" << location.first_line << "$" << (autoidx++);
+		sstr << "$mem2reg_wr$" << children[0]->str << "$" << RTLIL::encode_filename(filename) << ":" << location.first_line << "$" << (autoidx++);
 		std::string id_addr = sstr.str() + "_ADDR", id_data = sstr.str() + "_DATA";
 
 		int mem_width, mem_size, addr_bits;
@@ -4962,7 +4962,7 @@ bool AstNode::mem2reg_as_needed_pass2(pool<AstNode*> &mem2reg_set, AstNode *mod,
 		else
 		{
 			std::stringstream sstr;
-			sstr << "$mem2reg_rd$" << str << "$" << filename << ":" << location.first_line << "$" << (autoidx++);
+			sstr << "$mem2reg_rd$" << str << "$" << RTLIL::encode_filename(filename) << ":" << location.first_line << "$" << (autoidx++);
 			std::string id_addr = sstr.str() + "_ADDR", id_data = sstr.str() + "_DATA";
 
 			int mem_width, mem_size, addr_bits;
diff --git a/frontends/verific/verific.cc b/frontends/verific/verific.cc
index ab527a253..e0dbe1b32 100644
--- a/frontends/verific/verific.cc
+++ b/frontends/verific/verific.cc
@@ -183,7 +183,7 @@ RTLIL::IdString VerificImporter::new_verific_id(Verific::DesignObj *obj)
 {
 	std::string s = stringf("$verific$%s", obj->Name());
 	if (obj->Linefile())
-		s += stringf("$%s:%d", Verific::LineFile::GetFileName(obj->Linefile()), Verific::LineFile::GetLineNo(obj->Linefile()));
+		s += stringf("$%s:%d", RTLIL::encode_filename(Verific::LineFile::GetFileName(obj->Linefile())).c_str(), Verific::LineFile::GetLineNo(obj->Linefile()));
 	s += stringf("$%d", autoidx++);
 	return s;
 }
@@ -2828,9 +2828,11 @@ struct VerificPass : public Pass {
 			for (auto &ext : verific_libexts)
 				veri_file::AddLibExt(ext.c_str());
 
-			while (argidx < GetSize(args))
-				file_names.Insert(args[argidx++].c_str());
-
+			while (argidx < GetSize(args)) {
+				std::string filename(args[argidx++]);
+				rewrite_filename(filename);
+				file_names.Insert(strdup(filename.c_str()));
+			}
 			if (!veri_file::AnalyzeMultipleFiles(&file_names, verilog_mode, work.c_str(), veri_file::MFCU)) {
 					verific_error_msg.clear();
 					log_cmd_error("Reading Verilog/SystemVerilog sources failed.\n");
@@ -2843,36 +2845,48 @@ struct VerificPass : public Pass {
 #ifdef VERIFIC_VHDL_SUPPORT
 		if (GetSize(args) > argidx && args[argidx] == "-vhdl87") {
 			vhdl_file::SetDefaultLibraryPath((proc_share_dirname() + "verific/vhdl_vdbs_1987").c_str());
-			for (argidx++; argidx < GetSize(args); argidx++)
-				if (!vhdl_file::Analyze(args[argidx].c_str(), work.c_str(), vhdl_file::VHDL_87))
-					log_cmd_error("Reading `%s' in VHDL_87 mode failed.\n", args[argidx].c_str());
+			for (argidx++; argidx < GetSize(args); argidx++) {
+				std::string filename(args[argidx]);
+				rewrite_filename(filename);
+				if (!vhdl_file::Analyze(filename.c_str(), work.c_str(), vhdl_file::VHDL_87))
+					log_cmd_error("Reading `%s' in VHDL_87 mode failed.\n", filename.c_str());
+			}
 			verific_import_pending = true;
 			goto check_error;
 		}
 
 		if (GetSize(args) > argidx && args[argidx] == "-vhdl93") {
 			vhdl_file::SetDefaultLibraryPath((proc_share_dirname() + "verific/vhdl_vdbs_1993").c_str());
-			for (argidx++; argidx < GetSize(args); argidx++)
-				if (!vhdl_file::Analyze(args[argidx].c_str(), work.c_str(), vhdl_file::VHDL_93))
-					log_cmd_error("Reading `%s' in VHDL_93 mode failed.\n", args[argidx].c_str());
+			for (argidx++; argidx < GetSize(args); argidx++) {
+				std::string filename(args[argidx]);
+				rewrite_filename(filename);
+				if (!vhdl_file::Analyze(filename.c_str(), work.c_str(), vhdl_file::VHDL_93))
+					log_cmd_error("Reading `%s' in VHDL_93 mode failed.\n", filename.c_str());
+			}
 			verific_import_pending = true;
 			goto check_error;
 		}
 
 		if (GetSize(args) > argidx && args[argidx] == "-vhdl2k") {
 			vhdl_file::SetDefaultLibraryPath((proc_share_dirname() + "verific/vhdl_vdbs_1993").c_str());
-			for (argidx++; argidx < GetSize(args); argidx++)
-				if (!vhdl_file::Analyze(args[argidx].c_str(), work.c_str(), vhdl_file::VHDL_2K))
-					log_cmd_error("Reading `%s' in VHDL_2K mode failed.\n", args[argidx].c_str());
+			for (argidx++; argidx < GetSize(args); argidx++) {
+				std::string filename(args[argidx]);
+				rewrite_filename(filename);
+				if (!vhdl_file::Analyze(filename.c_str(), work.c_str(), vhdl_file::VHDL_2K))
+					log_cmd_error("Reading `%s' in VHDL_2K mode failed.\n", filename.c_str());
+			}
 			verific_import_pending = true;
 			goto check_error;
 		}
 
 		if (GetSize(args) > argidx && (args[argidx] == "-vhdl2008" || args[argidx] == "-vhdl")) {
 			vhdl_file::SetDefaultLibraryPath((proc_share_dirname() + "verific/vhdl_vdbs_2008").c_str());
-			for (argidx++; argidx < GetSize(args); argidx++)
-				if (!vhdl_file::Analyze(args[argidx].c_str(), work.c_str(), vhdl_file::VHDL_2008))
-					log_cmd_error("Reading `%s' in VHDL_2008 mode failed.\n", args[argidx].c_str());
+			for (argidx++; argidx < GetSize(args); argidx++) {
+				std::string filename(args[argidx]);
+				rewrite_filename(filename);
+				if (!vhdl_file::Analyze(filename.c_str(), work.c_str(), vhdl_file::VHDL_2008))
+					log_cmd_error("Reading `%s' in VHDL_2008 mode failed.\n", filename.c_str());
+			}
 			verific_import_pending = true;
 			goto check_error;
 		}
diff --git a/kernel/rtlil.h b/kernel/rtlil.h
index ff5bdf2d7..db175d7e9 100644
--- a/kernel/rtlil.h
+++ b/kernel/rtlil.h
@@ -440,6 +440,21 @@ namespace RTLIL
 		}
 	};
 
+	static inline std::string encode_filename(const std::string &filename)
+	{
+		std::stringstream val;
+		if (!std::any_of(filename.begin(), filename.end(), [](char c) { 
+			return static_cast<unsigned char>(c) < 33 || static_cast<unsigned char>(c) > 126; 
+		})) return filename;
+		for (unsigned char const c : filename) {
+			if (c < 33 || c > 126)
+				val << stringf("$%02x", c);
+			else 
+				val << c;
+		}
+		return val.str();
+	}
+
 	// see calc.cc for the implementation of this functions
 	RTLIL::Const const_not         (const RTLIL::Const &arg1, const RTLIL::Const &arg2, bool signed1, bool signed2, int result_len);
 	RTLIL::Const const_and         (const RTLIL::Const &arg1, const RTLIL::Const &arg2, bool signed1, bool signed2, int result_len);
diff --git a/passes/sat/qbfsat.cc b/passes/sat/qbfsat.cc
index 864d6f05d..1302b3383 100644
--- a/passes/sat/qbfsat.cc
+++ b/passes/sat/qbfsat.cc
@@ -216,7 +216,7 @@ QbfSolutionType call_qbf_solver(RTLIL::Module *mod, const QbfSolveOptions &opt,
 	QbfSolutionType ret;
 	const std::string yosys_smtbmc_exe = proc_self_dirname() + "yosys-smtbmc";
 	const std::string smtbmc_warning = "z3: WARNING:";
-	const std::string smtbmc_cmd = stringf("%s -s %s %s -t 1 -g --binary %s %s/problem%d.smt2 2>&1",
+	const std::string smtbmc_cmd = stringf("\"%s\" -s %s %s -t 1 -g --binary %s %s/problem%d.smt2 2>&1",
 			yosys_smtbmc_exe.c_str(), opt.get_solver_name().c_str(),
 			(opt.timeout != 0? stringf("--timeout %d", opt.timeout) : "").c_str(),
 			(opt.dump_final_smt2? "--dump-smt2 " + opt.dump_final_smt2_file : "").c_str(),
diff --git a/passes/techmap/abc.cc b/passes/techmap/abc.cc
index 0b9c327c0..656c36b84 100644
--- a/passes/techmap/abc.cc
+++ b/passes/techmap/abc.cc
@@ -789,15 +789,15 @@ void abc_module(RTLIL::Design *design, RTLIL::Module *current_module, std::strin
 	log_header(design, "Extracting gate netlist of module `%s' to `%s/input.blif'..\n",
 			module->name.c_str(), replace_tempdir(tempdir_name, tempdir_name, show_tempdir).c_str());
 
-	std::string abc_script = stringf("read_blif %s/input.blif; ", tempdir_name.c_str());
+	std::string abc_script = stringf("read_blif \"%s/input.blif\"; ", tempdir_name.c_str());
 
 	if (!liberty_files.empty() || !genlib_files.empty()) {
 		for (std::string liberty_file : liberty_files)
-			abc_script += stringf("read_lib -w %s; ", liberty_file.c_str());
+			abc_script += stringf("read_lib -w \"%s\"; ", liberty_file.c_str());
 		for (std::string liberty_file : genlib_files)
-			abc_script += stringf("read_library %s; ", liberty_file.c_str());
+			abc_script += stringf("read_library \"%s\"; ", liberty_file.c_str());
 		if (!constr_file.empty())
-			abc_script += stringf("read_constr -v %s; ", constr_file.c_str());
+			abc_script += stringf("read_constr -v \"%s\"; ", constr_file.c_str());
 	} else
 	if (!lut_costs.empty())
 		abc_script += stringf("read_lut %s/lutdefs.txt; ", tempdir_name.c_str());
@@ -1085,7 +1085,7 @@ void abc_module(RTLIL::Design *design, RTLIL::Module *current_module, std::strin
 			fclose(f);
 		}
 
-		buffer = stringf("%s -s -f %s/abc.script 2>&1", exe_file.c_str(), tempdir_name.c_str());
+		buffer = stringf("\"%s\" -s -f %s/abc.script 2>&1", exe_file.c_str(), tempdir_name.c_str());
 		log("Running ABC command: %s\n", replace_tempdir(buffer, tempdir_name, show_tempdir).c_str());
 
 #ifndef YOSYS_LINK_ABC
diff --git a/passes/techmap/abc9_exe.cc b/passes/techmap/abc9_exe.cc
index 7dc0a364b..2f46c89f4 100644
--- a/passes/techmap/abc9_exe.cc
+++ b/passes/techmap/abc9_exe.cc
@@ -175,12 +175,12 @@ void abc9_module(RTLIL::Design *design, std::string script_file, std::string exe
 	if (!lut_costs.empty())
 		abc9_script += stringf("read_lut %s/lutdefs.txt; ", tempdir_name.c_str());
 	else if (!lut_file.empty())
-		abc9_script += stringf("read_lut %s; ", lut_file.c_str());
+		abc9_script += stringf("read_lut \"%s\"; ", lut_file.c_str());
 	else
 		log_abort();
 
 	log_assert(!box_file.empty());
-	abc9_script += stringf("read_box %s; ", box_file.c_str());
+	abc9_script += stringf("read_box \"%s\"; ", box_file.c_str());
 	abc9_script += stringf("&read %s/input.xaig; &ps; ", tempdir_name.c_str());
 
 	if (!script_file.empty()) {
@@ -264,7 +264,7 @@ void abc9_module(RTLIL::Design *design, std::string script_file, std::string exe
 		fclose(f);
 	}
 
-	buffer = stringf("%s -s -f %s/abc.script 2>&1", exe_file.c_str(), tempdir_name.c_str());
+	buffer = stringf("\"%s\" -s -f %s/abc.script 2>&1", exe_file.c_str(), tempdir_name.c_str());
 	log("Running ABC command: %s\n", replace_tempdir(buffer, tempdir_name, show_tempdir).c_str());
 
 #ifndef YOSYS_LINK_ABC
diff --git a/tests/arch/ice40/.gitignore b/tests/arch/ice40/.gitignore
index 9a71dca69..54f908bdb 100644
--- a/tests/arch/ice40/.gitignore
+++ b/tests/arch/ice40/.gitignore
@@ -1,4 +1,5 @@
 *.log
+*.json
 /run-test.mk
 +*_synth.v
 +*_testbench
diff --git a/tests/gen-tests-makefile.sh b/tests/gen-tests-makefile.sh
index ab8fb7013..cde9ab1b9 100755
--- a/tests/gen-tests-makefile.sh
+++ b/tests/gen-tests-makefile.sh
@@ -17,7 +17,7 @@ generate_target() {
 generate_ys_test() {
 	ys_file=$1
 	yosys_args=${2:-}
-	generate_target "$ys_file" "$YOSYS_BASEDIR/yosys -ql ${ys_file%.*}.log $yosys_args $ys_file"
+	generate_target "$ys_file" "\"$YOSYS_BASEDIR/yosys\" -ql ${ys_file%.*}.log $yosys_args $ys_file"
 }
 
 # $ generate_bash_test bash_file
diff --git a/tests/tools/autotest.sh b/tests/tools/autotest.sh
index e4aef9917..f96eb8d71 100755
--- a/tests/tools/autotest.sh
+++ b/tests/tools/autotest.sh
@@ -1,6 +1,6 @@
 #!/usr/bin/env bash
 
-libs=""
+libs=()
 genvcd=false
 use_xsim=false
 use_modelsim=false
@@ -15,7 +15,7 @@ xinclude_opts=""
 minclude_opts=""
 scriptfiles=""
 scriptopt=""
-toolsdir="$(cd $(dirname $0); pwd)"
+toolsdir="$(cd "$(dirname "$0")"; pwd)"
 warn_iverilog_git=false
 # The following are used in verilog to firrtl regression tests.
 # Typically these will be passed as environment variables:
@@ -25,8 +25,8 @@ firrtl2verilog=""
 xfirrtl="../xfirrtl"
 abcprog="$toolsdir/../../yosys-abc"
 
-if [ ! -f $toolsdir/cmp_tbdata -o $toolsdir/cmp_tbdata.c -nt $toolsdir/cmp_tbdata ]; then
-	( set -ex; ${CC:-gcc} -Wall -o $toolsdir/cmp_tbdata $toolsdir/cmp_tbdata.c; ) || exit 1
+if [ ! -f "$toolsdir/cmp_tbdata" -o "$toolsdir/cmp_tbdata.c" -nt "$toolsdir/cmp_tbdata" ]; then
+	( set -ex; ${CC:-gcc} -Wall -o "$toolsdir/cmp_tbdata" "$toolsdir/cmp_tbdata.c"; ) || exit 1
 fi
 
 while getopts xmGl:wkjvref:s:p:n:S:I:A:-: opt; do
@@ -38,7 +38,7 @@ while getopts xmGl:wkjvref:s:p:n:S:I:A:-: opt; do
 		G)
 			warn_iverilog_git=true ;;
 		l)
-			libs="$libs $(cd $(dirname $OPTARG); pwd)/$(basename $OPTARG)";;
+			libs+=("$(cd "$(dirname "$OPTARG")"; pwd)/$(basename "$OPTARG")");;
 		w)
 			genvcd=true ;;
 		k)
@@ -162,7 +162,7 @@ do
 			cp ../${bn}_tb.v ${bn}_tb.v
 		fi
 		if $genvcd; then sed -i 's,// \$dump,$dump,g' ${bn}_tb.v; fi
-		compile_and_run ${bn}_tb_ref ${bn}_out_ref ${bn}_tb.v ${bn}_ref.${refext} $libs \
+		compile_and_run ${bn}_tb_ref ${bn}_out_ref ${bn}_tb.v ${bn}_ref.${refext} "${libs[@]}" \
 					"$toolsdir"/../../techlibs/common/simlib.v \
 					"$toolsdir"/../../techlibs/common/simcells.v
 		if $genvcd; then mv testbench.vcd ${bn}_ref.vcd; fi
@@ -171,11 +171,11 @@ do
 		test_passes() {
 			"$toolsdir"/../../yosys -b "verilog $backend_opts" -o ${bn}_syn${test_count}.v "$@"
 			compile_and_run ${bn}_tb_syn${test_count} ${bn}_out_syn${test_count} \
-					${bn}_tb.v ${bn}_syn${test_count}.v $libs \
+					${bn}_tb.v ${bn}_syn${test_count}.v "${libs[@]}" \
 					"$toolsdir"/../../techlibs/common/simlib.v \
 					"$toolsdir"/../../techlibs/common/simcells.v
 			if $genvcd; then mv testbench.vcd ${bn}_syn${test_count}.vcd; fi
-			$toolsdir/cmp_tbdata ${bn}_out_ref ${bn}_out_syn${test_count}
+			"$toolsdir/cmp_tbdata" ${bn}_out_ref ${bn}_out_syn${test_count}
 			test_count=$(( test_count + 1 ))
 		}